The term Sturgeon includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common names, notably sterlet, kaluga and beluga. Collectively, the family is also known as the True Sturgeons. They are distinctive for their elongated bodies, lack of scales, and occasional great size: Sturgeons ranging from 7–12 feet (2-3½ m) in length are common, and some species grow up to 18 feet (5.5 m). Most sturgeons are anadromous bottom-feeders, spawning upstream and feeding in river deltas and estuaries. While some are entirely freshwater, very few venture into the open ocean beyond near coastal areas.

The American plaice or sole, Hippoglossoides platessoides, is a flatfish that belongs, along with other right eyed flounders, to the Pleuronectidae family. Their range is from southern Labrador to Rhode Island. They spawn in the Gulf of Maine, with peak activity in April and May. They grow to a maximum length of 70 cm (28 inches). The species is considered by the Northwest Atlantic Fisheries Organization to be overfished, with no signs of recovery. American plaice may be an intermediate host for the nematode parasite Otostrongylus circumlitis, which is a lungworm of seals, primarily affecting animals less than 1 year of age.

The term worm is used to describe many different distantly-related animals which have a long cylindrical body and no legs. In everyday language, the term worm is also applied to various other living forms such as larvae, insects, centipedes, shipworms (teredo worms), or even some vertebrates (creatures with a backbone) such as blindworms and caecilians. Worms vary in size from microscopic to over a metre in length for marine polychaete worms (bristle worms), 6.7 m (22 ft) for the African giant earthworm, Microchaetus rappi, and 55 m (180 ft) for the marine nemertean worm (bootlace worm), Lineus longissimus.